b'Figure 2. Optical micrographs showing cross-sectional microstructure of hot-rolled and annealed C26M base alloys with Y or Zr additions.stability was significant, even atthe Zr addition promoted internal 1,000C, as shown in Figure 2.oxidation to decrease the oxidation The fine grain structure resulted inresistance during ramp test in steam increasing the room-temperatureenvironments up to 1450C (Figure ductility for up to ~60% without4). The Y added alloys (with no Zr), any trade-off of the tensile strengthson the other hand, showed improved (Figure 3). The wide temperatureoxidation resistance with protective tolerance with the high grain- alumina-scale formation at the same size stability during annealingtest condition. The observed improved will be a significant advantage inproperties suggested that the C26M maintaining processability withbase alloys still hold a potential various combinations of hot- andopportunity to optimize the balanced cold-process, including seamless,and further improved properties thin-wall FeCrAl tube productionthrough refining the combination of (e.g., large drawing reduction perminor alloying additions.pass). However, it was also found that 82 2019|AFC ACCOMPLISHMENTS'